Using a Punnett Square for a dihybrid cross, whats the percentages of genotypes and phenotypes for their offspring if a couple is heterozygous for eye color and hair color?

Question

(You can choose the letters of alleles to use). Brown hair and Brown eyes are dominant over Blonde hair and Blue eyes

Answer 1

Hi,

This question is a bit tricky but doing the old fashion punnet square really helps to see what is happening. When considering the results genotypes and phenotypes need to be considered slightly differently. Ultimately the dihybrid cross would result in primarily with the most of the children being heterozygous in these traits. Phenotypicaly, however, it would appear as the majority of children would have the Brown hair and Brown eyes traits. The small remainder would just have either Blonde Hair, Blue Eyes, or both.

-KS